Systems and methods of adaptive beamforming for mobile satellite systems based on user locations and co-channel waveforms

1. A method of beamforming for a satellite system, the method comprising:

constructing a virtual transmit array co-variance matrix based on locations, power, and bandwidth allocations of a plurality of active co-channel user equipments;

generating, with a ground based beamformer, a customized user beam that maximizes a gain towards a desired user equipment of the plurality of active co-channel user equipments while minimizing a plurality of gains towards all others of the plurality of active co-channel user equipments, the desired user equipment having a location and transmitting a known pilot signal;

wherein the ground based beamformer interfaces with a plurality of antennas on a feederlink side of a satellite and a plurality of beam ports on a satellite base station subsystem side;

wherein the ground based beamformer is operated in a transparent mode, whereby individual antennas of the satellite are connected to individual beam ports using a complex weight vector.

2. The method of claim 1 , further comprising:

setting a real part of a first weight element of the complex weight vector to a non-zero value;

setting an imaginary part of the first weight element to zero; and

for each of a plurality of additional weight elements of the complex weight vector,

setting a real part of the additional weight element to zero, and

setting an imaginary part of the additional weight element to zero.

3. The method of claim 2 , further comprising:

selecting the first weight element based on a particular feed element connected to the satellite base station subsystem.

4. The method of claim 1 , wherein generating a customized user beam includes generating a customized user beam for a return link of the satellite system.

5. The method of claim 4 , wherein generating a customized user beam for a return link includes maximizing a signal to noise and interference ratio of a signal received from the desired user equipment.

6. The method of claim 4 , further comprising:

receiving, by the ground-based beamformer,

complex baseband signals from an antenna array of a satellite of the satellite system;

wherein generating a customized user beam for a return link includes

analyzing the complex baseband signals, and

maximizing a signal to noise and interference ratio of a signal received from the desired user equipment.

7. The method of claim 1 , further comprising:

transmitting, with the satellite base station subsystem, complex baseband signals to individual elements of an antenna array on a satellite.

8. The method of claim 7 , further comprising:

passing the complex baseband signals through the ground-based beamformer.

9. A system for beamforming in a satellite communication network, the system comprising:

an electronic processor communicatively coupled to a satellite system and configured to:

construct a virtual transmit array co-variance matrix based on locations, power, and bandwidth allocations of a plurality of active co-channel user equipments;

generate, with a ground-based beamformer that interfaces with a plurality of antennas on a feederlink side of a satellite and a plurality of beam ports on a satellite base station subsystem side, a customized user beam that maximizes a gain towards a desired user equipment of the plurality of active co-channel user equipments while minimizing a plurality of gains towards all others of the plurality of active co-channel user equipments, the desired user equipment having a location and transmitting a known pilot signal; and

operate the ground based beamformer in a transparent mode, whereby individual antennas of the satellite are connected to individual beam ports using a complex weight vector.

10. The system of claim 9 , wherein the electronic processor is configured to:

set a real part of a first weight element of the complex weight vector to a non-zero value;

set an imaginary part of the first weight element to zero; and

for each of a plurality of additional weight elements of the complex weight vector,

set a real part of the additional weight element to zero, and

set an imaginary part of the additional weight element to zero.

11. The system of claim 10 , wherein the electronic processor is configured to:

select the first weight element based on a particular feed element connected to the satellite base station subsystem.

12. The system of claim 9 , wherein the electronic processor is configured to:

generate the customized user beam for a return link of the satellite system.

13. The system of claim 12 , wherein the electronic processor is configured to:

generate the customized user beam by maximizing a signal to noise and interference ratio of a signal received from the desired user equipment.

14. The system of claim 12 , wherein the electronic processor is configured to:

receive complex baseband signals from an antenna array of a satellite of the satellite system; and

generate a customized user beam for a return link by

analyzing the complex baseband signals, and

maximizing a signal to noise and interference ratio of a signal received from the desired user equipment.

15. The system of claim 9 , wherein the electronic processor is configured to:

transmit, with the satellite base station subsystem, complex baseband signals to

individual elements of an antenna array on a satellite by passing the complex baseband signals

through the ground-based beamformer.

16. The system of claim 15 , wherein the generation of the customized user beam is integrated into the satellite base station subsystem.